Proper transcode workflow for LUMIX 4K files

So I wanted to transcode everything into avid as ProRes HQ MXF files. AMA linked some R3D files, then transcode those fine. The LUMIX 4K files would not import without error, so I used MPEG stream clip to make 1920x1080 ProRes, then imported into AVID. Some of those files now play back with a little bit of grain or something. Just checking if I did the proper workflow.

The resize algorithm may have added some high frequency artifacts that could appear as"noise" or "grain". Did toy have better down sampling checked? I also wonder if MPEG Streamclip decodes greater than 2K as well as it should, perhaps it does. I would try with something like Resolve directly to MXF/DNxHD to see if there is any difference. I don't have any sample 4K LUMIX to try myself, but if you had a file you can spare that shows the artifacting, I'll be willing to play with it to see what's going on. Use yousendit.com or filemail.com and email to me at michael[at]24p[dot]com